Fission cross-section measurements of 237Np, 242m Am, and 245Cm with lead slowing-down neutron spectrometer

The cross sections for neutron-induced fission of 237Np, Am, and 245Cm have been measured in the energy range from 0.1 eV to 2 keV using the lead slowing-down neutron spectrometer at the Research Reactor Institute, Kyoto University. The fission cross sections were deduced relative to those for 235U(n,f) and 10B(n,a). The cross section for 237Np(n,f) was obtained with the experimental uncertainty of about 20% in the energy region below 25 eV and typically 13% above this energy. The experimental uncertainties for 242m Am and 245Cm were, respectively, of the order of 14% and 9% in the entire energy region.